Donald Trump has suggested that climate change will ‘change back again’ and that he doesn’t know that it’s manmade.
Photograph: Kevin Lamarque/Reuters

Asked about climate change on CBS’s 60 Minutes and by reporters in Georgia on Monday, Donald Trump suggested that climate change will “change back again”,” that it might not be manmade, and that hurricanes aren’t getting worse. The Guardian compared the US president’s comments with the science.

Trump: ‘Something’s changing and it’ll change back again’

Verdict: False The UN’s Intergovernmental Panel on Climate Change has found that temperatures will not stop rising without significant changes to how humans live, including a rapid phase-out of fossil fuels.

Trump: ‘I don’t know that it’s manmade’

Verdict: False The US government’s own Climate Science Special Report, published under Trump, finds that “it is extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-20th century,” and that over the last century “there is no convincing alternative explanation supported by the extent of the observational evidence.”

Trump: ‘I don’t wanna give trillions and trillions of dollars. I don’t wanna lose millions and millions of jobs. I don’t wanna be put at a disadvantage’

Verdict: Misleading Limiting temperatures to rising to 1.5C, rather than 2C, would save the global economy more than $20tn, according to a peer-reviewed study in the journal Nature. A working paper from the Federal Reserve Bank of Richmond found that global warming could substantially slow economic growth in the US, especially in places where people voted for Trump. Climate change cost US taxpayers more than $350bn over the past decade, according to the federal watchdog the Government Accountability Office.

On melting ice caps causing sea-level rise, Trump said: ‘And you don’t know whether or not that would have happened with or without man’

Verdict: False Ice caps are melting because of rising temperatures due to human activity. In 2017, global mean sea level was 77mm (or 3in) above the 1993 average, according to the US National Oceanic and Atmospheric Administration. “The rising water level is mostly due to a combination of meltwater from glaciers and ice sheets and thermal expansion of seawater as it warms,” Noaa concludes. In the US, almost 40% of the population lives in densely inhabited coastal areas at risk for flooding, shoreline erosion and hazards from storms.

Trump: ‘They say that we had hurricanes that were far worse than what we just had with Michael’

Verdict: Misleading Hurricane Allen in 1980 did have a higher wind speed than Hurricane Michael, clocking in a 190mph. But the number of named storms has increased since the start of the 20th century. Hurricanes are expected to become stronger as they will form in warmer waters. Sea-level rise will exacerbate storm surge and flooding. Rising oceans also will inundate barrier islands and other features that have protected communities. At the same time, coastal cities have developed quickly, putting more infrastructure and people at risk.

Trump: ‘They say the worst hurricanes were 50 years ago, if you can believe it. In fact, the one that they say was worse – so two or three worse – one was in 1890s, and one was exactly 50 years ago. The winds were 200 miles an hour. So who knows?’

Verdict: Misleading While some storms in years past have had higher wind speeds, the most named hurricanes – 28 in total – occurred in 2005. In the past 24 years, there have been 15 above normal hurricane seasons, the worst on record. Improvements in radar and hurricane warning systems have helped to limit the number of deaths from dangerous storms. Hurricane Maria in Puerto Rico last year killed at least around 3,000 people. Hurricane Katrina, which was made worse by human failures in storm protection, killed more than 1,800 in 2005.